how to fix P0301 misfire code on BMW 5 Series F10/F11 (2010-2017)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Ensure the engine is cool and disconnect the negative battery terminal.

2. Replace Spark Plug

• Tools Required: Socket set, spark plug socket, torque wrench.
• Remove the ignition coil from cylinder 1 by unscrewing the bolts and gently pulling it out.
• Use a spark plug socket to remove the old spark plug. Inspect it for fouling or damage.
• Install the new spark plug, ensuring it is gapped correctly per manufacturer specifications (usually around 0.028-0.032 inches).
• Torque the spark plug to the manufacturer's specification (typically around 18-22 lb-ft).
• Reinstall the ignition coil and connect the electrical connector securely.

3. Check and Replace Ignition Coil (if needed)

• If the spark plug replacement did not resolve the issue, proceed to check the ignition coil.
• Swap the cylinder 1 ignition coil with another cylinder’s coil and clear the codes.
• If the misfire moves to the other cylinder, replace the faulty ignition coil with a new one.

4. Inspect and Clean Fuel Injector (if needed)

• If the ignition coil is functioning correctly, inspect the fuel injector for cylinder 1.
• Remove the fuel injector connector and unscrew the injector from the rail.
• Clean the injector with a specialized injector cleaner or replace it if clogged or damaged.
• Reinstall the injector and reconnect the electrical connector.

5. Perform Compression Test (if needed)

• If issues persist, perform a compression test on cylinder 1.
• Remove the spark plug and insert the compression tester into the spark plug hole.
• Crank the engine and record the compression reading.
• Compare the reading with manufacturer specifications; if low, further investigation is needed for internal engine issues.